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How much water is too much?

3 minute read
young man who's just finished a marathon run drinking from a water bottle

It’s a vital part of every cell and makes up a whopping 60% of our bodies, but did you know that water can be deadly? It may sound strange, but in the case of h2o, you can have too much of a good thing.

It’s called ‘water intoxication’ and it happens when you drink more fluid than your kidneys can excrete.

Those who participate in endurance activities like long-distance riding, running and hiking tend to be more susceptible to water intoxication, in fact a 2002 study found that 13% of Boston Marathon runners finished the race with hyponatremia (when the sodium levels in the blood are too low).

Can you drown from drinking too much water?

Studies have reported that your kidneys are capable of processing 20-28 litres of water per day, but they can’t handle more than about a litre each hour.

So you shouldn’t be consuming more than a litre of the wet stuff every hour.

If you drink too much water, it can lead to dangerous dilution of the electrolytes in your blood, particularly sodium. Your brain cells swell, which causes pressure on the skull, and you might experience symptoms such as headaches, blurred vision, vomiting or cramping. If you think you may be at risk of water intoxication, you should seek medical attention immediately because in severe cases, it can lead to seizures, brain damage, coma and even death.

young blonde woman drinking water from her kitchen tap

How much should I be drinking?

This is where it gets tricky because the guidelines for exactly how much water you should be drinking are different for everyone depending on your weight, sex, amount of exercise you do and climate.

Better Health explains that the average adult requires between 2.1-2.6 litres of water per day, but if you are physically active, live in a warmer climate, are on a special diet or you’re pregnant or breastfeeding, you’ll probably need to increase this amount.

If you need some advice on your own water intake, head to your GP, nutritionist or dietitian. At nib, we offer a number of Extras covers that pay benefits towards your nutritionist and dietitian consultations. Log in to Online Services to see if you’re covered and to check your annual limits.

We’ve partnered with the Mark Hughes Foundation to trek the Sandakan Death March and follow in the footsteps of Aussie WWII prisoners of war who faced debilitating heat, starvation and often fatal injuries. Of the 2,000+ Sandakan prisoners, only six Australians survived; so in the lead up to the October 2018 trek, we’ll be releasing a series of articles on the incredible limits of the human body. To find out more about the trek, or to donate visit the Mark Hughes Everyday Hero page.

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